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Predator flies to destroy piti
makuna
By Risidra Mendis
A
species of flies known as parasitoids is to be brought
down from Puerto Rico to control the spread of the piti
makuna.
The
Sunday Leader learns that 50,000 parasitoids are to be
brought into the country by April to control the spread
of the piti makuna which is known to attack plants and
trees that exude milk.
The
programme to bring in the parasitoids will be funded by
the United States Agriculture Department (USAD) Animal
and Plant Health Inspection Service.
The
piti makuna also known as the mealy bug by Horticultural
Crops, Research and Development Institute (HCRDI)
officials, is believed to have entered the country in
mid 2007 and has so far destroyed many vegetable and
fruit cultivations mainly in Colombo and Gampaha areas.
Head,
Division of Entomology (HCRDI) Indra Wahundeniya said
this was the first time the mealy bug has affected
papaya and many other varieties of vegetables and fruit
plants in the country.
"We
believe this bug was illegally brought in to the country
with plant materials. The mealy bug has no natural
enemies to control its numbers. This is the main reason
for the mealy bug to increase in numbers within a short
period and reach epidemic levels," Wahundeniya said.
She
added that in such cases cultural and chemical control
methods introduced by the Agriculture Department were
only temporary and it was necessary to introduce a
natural enemy to control the spread of the pest. "It has
been recorded that over 25 countries around the world
including Mexico and South America have faced the same
problems with these pests.
"The
parasitoid was the best option, as these insects are
known to lay eggs on the mealy bugs. The parasitoids
have a four stage life cycle namely the eggs, the
larvae, the pupa and the adult insect. Once the
parasitoid completes its life cycle the mealy bug will
reduce in numbers," Wahundeniya explained.
Wahundeniya went on to say that some of the 50,000
parasitoids brought down will be kept in the
laboratories to multiply and the others released to
badly affected areas in the country.
"We
are still not sure if 50,000 parasitoids will be enough
to control the spread of the mealy bug as the situation
is very serious in some areas. At present we are
awaiting instructions from USAD as to whether we can
immediately release the insects to the environment or
wait for a few days until the parasitoids get used to
the Sri Lankan climate," Wahundeniya said.
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